What does "Dark Background " mean TT terminology


Is there some sort of dictionary that would explain these audiophile terminologies? What ever happen to "sounds great", "very life like". When I'm talking to somebody describing the characteristics of an audio gear, 1/2 of the term I don't understand. All I know is that, my system sounds amazing.
justubes
I take it as when there is no music playing the system is very quiet. If it is not dark then there is some hiss even though there is no music playing.
To me dark background is when I listen at night with the lights off. Solid state of course, as tubes tend to lighten it up. Hope that helps. just kidding!!!